The proposed work will explore mediated integration of data resources in the neuroscience community. The propossed mediator system, the Query Integrator Server, (QIS) is intended to faciliate interoperation between such resources by leveraging various semantic data models developed by other neuroinformatics researchers, in addition to using technologies derived from version-control and ontology research. Proof of concept will be obtained by close collaboration with two groups that are associated with the Human Brain Project: Biomedical Informatics Research Network (BIRN)-affiliated investigators from the University of California, San Diego, who are also working in the field of query mediation for federated databases, and the Gardner group at Cornell University, which is working on common semantic data models for neuroscience.